A set of 50 photographs and associated handwritten descriptive notes, acquired from the Imperial Russian Geographical Society in St. Petersburg. The complete notes, "1904 View of Great Tibet", are available at: http://collections.lib.uwm.edu/u?/tibet,94

Tan-gye-ling [Tengyeling] from the SE. [Z.]
This is Demu-khutuktu's [Demohutuktu], or late regent (+August 1900) monastic palace. In the distance are Ch'agpori [Chagpori] on the left and Potala on the right of this picture. Tan-gye-ling [Tengye-ling], itself is on the second plan, the flat roofed building in the foreground being a private house. On the utmost left is a group of Dar-cog [Da-cha or dar-lch'og or Dar Cho] (prayer flags).
Obs. Tangia Ling on A-K's Plan of Lhasa, See also Waddell's Buddhism [Waddell, L.A. , The Buddhism of Tibet or Lamaism] p. 522. Tangye-ling Rockhill l.c. Plan. Tan-gye Ling on Waddell's Plan of Lhasa. GJ.[Geographical Journal] III, 1904.

"A regent is necessary to conduct the temporal government, especially under the system of papal succession by re-births, where the new Dalai Lama does not reach his majority and nominal succession to temporal rule till his eighteenth year. In order to avoid plotting against hierarchies, Nag-wan ruled that the regent must be a Lama, and he restricted this office to the head Lamas of the monastic palaces or Ling of Lhasa, named Tan-gye-ling, Kun-de-ling, Ts'ech'og-ling, and Ts'amo-ling." (p.253).
Waddell, L.A. (1899). The Buddhism of Tibet or Lamaism. London: Luzac & Co. Available through Google Books at: http://books.google.com/books?id=V-DJFl8VBhEC&pg=RA1-PR7&d